[Potironette]

During class, a couple of students talked here and there, but the teacher didn't take off participation points.

Luck didn't take any notes because there truly wasn't any notes worth taking. Math class was rarely about notes. It was about putting examples up at the board, solving them with the class, then practicing at home.
Beside him, Blitzel was solving things Luck couldn't understand. It related to the class, but obviously wasn't what the teacher was putting up at the board.

The teacher was saying something about graphs, "...range of the sine becomes domain of the inverse sine. So it is between -1 and 1 for inverse sine. The domain of the sine becomes the range of the inverse sine. Only it needs to be restricted to negative pi over two and pi over two. Can someone tell me me why?"
No one raised their hand.
"Luck?"

Luck looked at the teacher gravely. He had no idea.
"Because otherwise it's not a function." Blitzel piped up.
"Because then it's not a function." Luck repeated.

The teacher glared at Blitzel. "Alright, Blitzel, can you tell me why it's not a function then?"
"Gladly." Said Blitzel grinning. "It's because a function can only have one y-value for every x-value. So you need to restrict the domain of the sine graph, or the range of the inverse sine graph."

The teacher nodded in assent before moving on with the lesson.